Table 2.
Multivariatea-adjusted geometric mean and 95 % confidence interval (CI) for percent dense breast volume by quartiles of estrogens and progesterone at pre-b and postmenarchealc period
| Premenarche | Postmenarche | |||||
|---|---|---|---|---|---|---|
| Quartiles | Follicular phased | Luteal phased | ||||
| Mean | (95 % CI) | Mean | (95 % CI) | Mean | (95 % CI) | |
| Estradiol | N = 153 | N = 110 | N = 88 | |||
| Q1 | 17.3 | (11.1-21.0) | 17.1 | (11.7-25.0) | 16.7 | (11.6-23.9) |
| Q2 | 18.3 | (12.4-27.0) | 23.6 | (19.8-28.1) | 15.3 | (10.7-21.9) |
| Q3 | 17.6 | (14.6-21.2) | 15.0 | (10.3-21.8) | 19.4 | (15.2-24.8) |
| Q4 | 21.5 | (18.9-24.4) | 17.5 | (13.8-22.2) | 17.8 | (12.4-25.6) |
| P-trende | 0.26 | 0.42 | 0.43 | |||
| Non-SHBG-bound estradiol | N = 151 | N = 106 | N = 88 | |||
| Q1 | 17.8 | (12.1-26.2) | 17.6 | (13.5-23.0) | 18.2 | (12.7-26.2) |
| Q2 | 20.3 | (14.0-29.6) | 22.7 | (16.1-32.2) | 12.3 | (10.5-14.3) |
| Q3 | 16.3 | (11.7-22.9) | 14.9 | (12.6-17.7) | 22.0 | (17.8-27.2) |
| Q4 | 19.6 | (16.6-23.1) | 17.7 | (13.2-23.8) | 18.0 | (13.1-24.8) |
| P-trende | 0.78 | 0.24 | 0.43 | |||
| Estrone | N = 153 | N = 110 | N = 88 | |||
| Q1 | 18.1 | (12.3-26.6) | 15.5 | (12.1-19.8) | 16.2 | (13.5-20.9) |
| Q2 | 18.0 | (14.0-23.2) | 19.7 | (13.1-29.7) | 17.2 | (10.1-29.4) |
| Q3 | 21.4 | (15.3-29.8) | 18.3 | (14.5-23.0) | 17.4 | (11.9-25.4) |
| Q4 | 17.1 | (13.0-22.5) | 18.8 | (14.3-24.8) | 17.6 | (12.6-24.5) |
| P-trende | 0.93 | 0.43 | 0.71 | |||
| Estrone sulfate | N = 146 | N = 110 | N = 88 | |||
| Q1 | 21.2 | (14.8-30.4) | 19.3 | (12.3-30.1) | 19.4 | (13.9-27.0) |
| Q2 | 15.2 | (9.9-23.5) | 14.9 | (12.1-18.2) | 13.8 | (12.2-15.8) |
| Q3 | 15.7 | (11.1-22.2) | 15.7 | (12.2-20.3) | 18.7 | (14.3-24.4) |
| Q4 | 22.5 | (18.9-26.9) | 23.4 | (21.2-25.8) | 17.7 | (13.1-23.8) |
| P-trende | 0.79 | 0.49 | 0.73 | |||
| Progesterone | N = 110 | N = 84 | ||||
| Q1 | – | 17.0 | (11.0-24.8) | 16.4 | (14.4-18.6) | |
| Q2 | – | 21.0 | (17.0-26.2) | 16.7 | (13.1-21.3) | |
| Q3 | – | 16.5 | (12.9-24.4) | 19.5 | (11.5-33.1) | |
| Q4 | – | 15.8 | (13.6-18.8) | 17.6 | (11.2-27.8) | |
| P-trende | 0.81 | 0.38 | ||||
Abbreviations: CI confidence interval, SHBG sex hormone-binding globulin
aGeometric means and 95 % CI are estimated from linear mixed-effects models including clinic as a random effect and adjusted for treatment group (diet intervention group, usual-care control group), BMI (kg/m2, continuous), parity (0 and >0), duration of hormone use (yrs, continuous), race (white and nonwhite), and education (bachelor's degree, graduate school and other) as fixed effects
bThe premenarcheal estrogen levels were standardized by adjusting for age at visit, BMI z-score at visit, and visit number in years after randomization by residual method
cThe postmenarcheal estrogens and progesterone levels were standardized by adjusting for age at visit, BMI z-score at visit, visit number in years after randomization and days from blood draw to start of next menses as a cubic spline by residual method
d.Days 1 through 14 before next menses were defined as luteal, whereas days 0 and greater than 14 were defined as follicular
e P-test for trend was conducted by modeling the quartile medians of standardized hormone concentrations as a continuous term in linear mixed-effects models and calculating the Wald test statistic